diff --git a/src/backend/postmaster/bgwriter.c b/src/backend/postmaster/bgwriter.c index 830cb897d9..ed1a7b2f27 100644 --- a/src/backend/postmaster/bgwriter.c +++ b/src/backend/postmaster/bgwriter.c @@ -37,7 +37,7 @@ * * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/postmaster/bgwriter.c,v 1.19 2005/08/20 23:26:17 tgl Exp $ + * $PostgreSQL: pgsql/src/backend/postmaster/bgwriter.c,v 1.20 2005/09/12 22:20:16 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -160,6 +160,7 @@ void BackgroundWriterMain(void) { sigjmp_buf local_sigjmp_buf; + MemoryContext bgwriter_context; Assert(BgWriterShmem != NULL); BgWriterShmem->bgwriter_pid = MyProcPid; @@ -207,6 +208,19 @@ BackgroundWriterMain(void) */ last_checkpoint_time = time(NULL); + /* + * Create a memory context that we will do all our work in. We do this + * so that we can reset the context during error recovery and thereby + * avoid possible memory leaks. Formerly this code just ran in + * TopMemoryContext, but resetting that would be a really bad idea. + */ + bgwriter_context = AllocSetContextCreate(TopMemoryContext, + "Background Writer", + ALLOCSET_DEFAULT_MINSIZE, + ALLOCSET_DEFAULT_INITSIZE, + ALLOCSET_DEFAULT_MAXSIZE); + MemoryContextSwitchTo(bgwriter_context); + /* * If an exception is encountered, processing resumes here. * @@ -247,9 +261,12 @@ BackgroundWriterMain(void) * Now return to normal top-level context and clear ErrorContext * for next time. */ - MemoryContextSwitchTo(TopMemoryContext); + MemoryContextSwitchTo(bgwriter_context); FlushErrorState(); + /* Flush any leaked data in the top-level context */ + MemoryContextResetAndDeleteChildren(bgwriter_context); + /* Now we can allow interrupts again */ RESUME_INTERRUPTS();